Since I dont know the Sundancer and have no idea of how much motor, speed and flying behavior it is about I`m not 100% sure, but; sounds like you should go for servoes with the double torque than the HS-55. Bluebird/Waypoint have some servoes with metal-gear, weighing 15,6 gram giving 3 times the torque, or the same one with plastic-gear slightly lighter and weaker. Hitec HS-81/85 is an alternative. And of course other brands at same size/torque...
The size of your pushrods again depends on airspeed and above all: lenght and connectors used. If your rudder/elevator servoes are placed up front look at the tiny Nyrods, cute, light and easy to install inside the fuse. Just remember to secure the outer tubes not only at the ends but 1-2 points in between too thus avoiding freeplay. 2mm or 2-56 is a safe size on pushrods used from servo to ailerons, then you are sure!
I would not have used parkflyer/micro accessories on this size birds, but there are lot of small and strong clevises and rudder-horns on the market.